New dog, 3 yr old male, neutered, yellow (Dudley lab? Lab mix) sometimes has a rug burn on the top of his nose; right where fur ends and nose begins. I've only seen him get it once (I don't think he knew I was watching). He was nosing around a blanket that was crumpled on the floor. It looked like he was smelling something at first, but then he bowed his head and made large sweeps, running the top of his nose along the carpet. This resulted in a rug burn that even bled a little! I've never seen him do it since, but sometimes I'll notice the rug burn on his nose is raw again. What's up with that??!

It's not a major cut, just a little rub - but what's going on here?? Is this a behavioral thing, or just a weird character?